1. Field of the Invention
The present invention is generally concerned with clutch release bearings, that is to say the parts which are intended, especially in automotive vehicles, to operate on the clutch release device of a clutch so as to disengage the latter.
2. Description of the Prior Art
As is known, a clutch release bearing of this kind generally comprises a first member, commonly known as the maneuvering member, which is adapted to be acted on by a control member, in practice a clutch release yoke, and a second member, commonly known as the drive member, which is adapted, when acted on by the maneuvering member, to operate on the clutch release device of the clutch to be controlled, and coupling means adapted to provide an appropriate axial linkage between said drive member and said maneuvering member.
The present invention is more particularly directed to the case where, in order to implement these coupling means, the maneuvering member comprises a transverse flange, which may be no more than a simple collar, and the drive member comprises a radial rim, there being provided for the purposes of securing the required axial retention of said drive member relative to said maneuvering member an axially acting annular spring which bears on the maneuvering member and on said radial rim of the drive member so as to urge the latter in the direction towards the flange of said maneuvering member.
This is the case, for example, in certain so-called self-centering clutch release bearings at least, in other words in certain at least of those clutch release bearings in which the drive member is free to move transversely in any direction relative to the maneuvering member, said drive member having an omnidirectional freedom of movement in contact with the flange of the latter or with a bearing part which bears axailly on said flange.
To be even more precise, this is the case with self-centering clutch release bearings of the maintained self-centering action type, in which, subject to the appropriately calibrated force applied by the axially acting annular spring employed, the drive member retains between two operations to disengage the clutch the same position relative to the maneuvering member as it occupied after the first of said clutch disengagement operations.
A maintained self-centering clutch release bearing of this type is described, for example, in French Pat. No. 2 465 119 filed on Sept. 10, 1979 under application No. 79 22532 in which, in the usual manner, the maneuvering member features an annular axial member on which the axially acting annular spring employed is adapted to bear.
In practice, this is a sleeve to the outside of which in the radial direction is rigidly attached the associated flange and on which the inside perimeter of the axially acting annular spring bears, its outside perimeter bearing axially on the corresponding radial rim of the drive member.
Conjointly, and in the usual manner, the drive member is a ball bearing of which each ring constitutes a generally annular member.
On assembling a clutch release bearing of this kind, which is effected by axial engagement of the drive member on the maneuvering member, the axially acting annular spring employed is inserted in advance into the interior of said drive member so that, as the latter advances, its internal periphery grips the sleeve of the maneuvering member, sliding along the latter as it advances.
For this axially acting annular spring to apply, when in service, a predetermined axial load to the drive member, there has to be a predetermined axial distance between its inside perimeter, through which it bears on the sleeve of the maneuvering member, and its outside perimeter, through which it bears on the radial rim of the drive member.
However, by virtue of its sliding during engagement of the drive member on the maneuvering member, there is inevitably on completion of such engagement an axial offset between the real position of its inside perimeter along the sleeve of the maneuvering member and the position which it should occupy in order for the required elastic force to be obtained.
In French patent application No. 2 465 119, in which the flange of the maneuvering member is integral with the sleeve of the latter, said flange and said sleeve forming a single part, it is proposed, to this end, to operate from the front, that is to say from the same side as the drive member, using an annular tool which, inserted between said drive member and the sleeve of the maneuvering member, is adapted to operate on the axially acting annular spring so as to force its inside perimeter along said sleeve of the maneuvering member to the final position required for the latter, materialized in practice by an abutment shoulder provided for this purpose on said sleeve, at a distance from the associated flange.
An arrangement of this kind is satisfactory.
It has disadvantages, however: it requires the use of an additional and special tool, and the use of this tool between the drive member and the sleeve of the maneuvering member necessitates the provision for this purpose of sufficient annular space between said drive member and said sleeve, which is prejudicial to the overall radial dimension of the assembly.
To overcome disadvantages like these, consideration might be given to separating the flange of the maneuvering member from the sleeve with which it is associated, so as to permit, on fitting the drive member, the outside perimeter of the axially acting annular spring employed to pass beyond the position which should be its final position until its inside perimeter is in the correct position and then to permit, by virtue of a retrograde movement of said flange relative to said sleeve, the outside perimeter of said spring to be placed in the required final position therefor, so obtaining the required elastic force.
This arrangement has it own disadvantages, however: after fitting the drive member to the maneuvering member it is necessary to provide specific means for ensuring appropriate axial positioning of the flange of said maneuvering member relative to the sleeve of the latter, and this arrangement involves working in two opposite axial directions, initially from the front for axial engagement of the drive member on the maneuvering member than from the rear for final positioning of said flange.
A general objective of the present invention is to provide an arrangement by means of which the disadvantages outlined above may be avoided.